Toe iron for safety ski bindings

ABSTRACT

A toe iron is mounted on a ski to be movable toward the tip of the ski and comprises a soleholder member, which engages the forward edge portion of the skiing boot from above. The soleholder member is held on the toe iron to be capable of a limited movement on a concave track in the form of an arc of a circle on both sides of its normal position, the radius of curvature of the track not being larger than the radius of the pivotal movement of the forward end of the boot.

United States Patent Inventor Hannes Marker Hauptstrasse 51-53, Garmisch- Partenkirchen, Germany App]. No. 787,103 Filed Dec. 26, 1968 Patented June 1, 1971 Priority Jan. 5, 1968 Germany P 16 78 275.5

TOE IRON FOR SAFETY SKI BINDINGS 3 Claims, 2 Drawing Figs.

US. Cl 280/1 1.35

Int. Cl A63c 9/00 Field of Search 280/1 1.35

1 1 References Cited UNITED STATES PATENTS 3,037,785 6/1962 DB Place 1280/1135 3,343,845 9/1967 Marker.... ZED/11.35 3,416,811 12/1968 Marker 280/11.35 3,451,687 6/1969 Voster et al. 280/1 1.35

Primary Examiner-Benjamin Hersh Assistant Examiner-Robert R. Song Alt0meyFleit, Gipple & Jacobson INVENTOR [1 8771725 Mar/Yer BY a I TOE IRON FOR SAFETY SKI BINDINGS This invention relates to a toe iron for safety ski bindings, in which toe irons comprising a soleholder member for engaging the forward edge portion of the sole of the boot from above are mounted on the ski for movement toward the tip of the ski.

Various types of such toe irons are known. The toe iron is either pivoted on a pivot pin, which is fixed to the ski, or is held and guided by a track, in the form of an arc of a circle, e.g., a dovetail guide, which track has a center of curvature that is disposed beyond the toe iron in the direction toward the tip of the ski. Another toe iron is initially movable transversely to the longitudinal direction of the ski and subsequently movable towardthe tip of the ski. The toe iron is retained in its normal position by resilient means, or is virtually rigid unless a predetermined deflecting force is applied. The resilient retain ing means have the advantage that they afford a shock-absorbing action.

All these toe irons must be and are movable toward the tip of the ski to ensure a release of the skiing boot. In the shockabsorbing toe iron, this movement has the disadvantage that the skiing boot automatically follows the movement of the toe iron in response to a force acting in the releasing sense and must be returned when the force is reduced before it has effected a release. Owing to the high friction which must be overcome, the restoring force acting on the toe iron is not sufficient in general to effect this return movement. In such case, the skiing boot is retained in the binding in an oblique position relative to the ski. This condition results in a fall, as a rule.

The virtually rigid toe irons do not involve a risk of retaining the skiing boot in the binding in a position which is oblique to the ski under the action of forces which are insufficient for a release and act obliquely or transversely to the longitudinal direction of the ski but they lack the shock-absorbing action, which is inherently desirable.

It is an object of the present invention to design a toe iron of the kind first previously described which avoids the risk of retaining the skiing boot in the binding in an oblique position relative to the ski, but affords a shock-absorbing action for the absorption of forces which act obliquely or transversely to the longitudinal direction of the ski and are harmless to the leg of the skier and do not result in a release.

In a toe iron for safety ski bindings, where the toe iron is mounted on the ski to be movable toward the tip of the ski and comprises a soleholder member, which engages the forward edge portion of the skiing boot from above, the object is accomplished according to the invention in that the soleholder member is held on the toe iron and is capable of a limited movement on a concave track in the form of an arc of a circle on both sides of its normal position. The radius of curvature of said track is not larger than the radius of the pivotal movement of the forward end of the boot.

Particularly when the radius of curvature of the soleholder member is equal to the radius of the pivotal movement of the forward end of the boot, it has proved desirable to provide a centering spring for holding the soleholder member in its normal position.

A development of the invention concerns a toe iron which is movable against the force of a spring element. In such a toe iron, it is desirable to use such spring element which serves also as a centering spring for the soleholder member.

An embodiment of the invention will now be described more fully with reference to the accompanying drawing, in which FIG. 1 is a central longitudinal sectional view showing a toe iron and FIG. 2 shows the toe iron in a top plan view tional view taken on line II-II of FIG. 1.

The toe iron according to the invention comprises substantially a baseplate l, which can be fixed with screws to the ski, a pivoted member 2 which is mounted on the baseplate, and a soleholder member 3, which is held on the pivoted member. A guide member 4 which is dovetail-shaped in cross section is partly in a secsecured to the baseplate l and has the curvature which is apparent from FIG. 2 The pivoted member 2 has a dovetailshaped groove 5 which mates the guide member 4 and owing to the cooperation of the guide member 4 and groove 5 is movable on the baseplate 1 toward both sides to an extent which is sufficient to release the toe portion of the boot. This displacement is effected against the force of a spring element 6, which is known with centering springs 7 being provided for holding the soleholder member in proper position. A spacing disc 12 consisting of a suitable material having a low coefficient of friction is provided between the baseplate l and the pivoted member 2.

According to the invention, the soleholder member 3 is held on the pivoted member 2 for limited movement on a concave track II having the shape of an arc ofa circle on both sides of its normal position. The radius of curvature of the track 11 is smaller in the present case than the radius ofthe pivotal movement of the forward end of the boot. During a pivotal movement of the boot about an axis which is adjacent to the heel, the boot is thus slightly moved rearwardly against the action of the heel-holding device. This results in an increase of the pressure which is applied by the boot against the toe iron so that the soleholder member is urged back by means of the boot to its initial position when the force which tends to impart a pivotal movement to the boot does not cause a release of the toe portion of the boot but is reduced before such release has been effected. This arrangement results in an automatic centering of the soleholder member. The soleholder member 3 has a dovetail-shaped retaining rib 15, which is dovetailshaped in cross section and slidably mounted in a mating track groove 11 of the pivoted member 2. The displacement of the soleholder member 3 is limited by a pin 13 which is held in the pivoted member 2 and has a free end portion engaging a central elongated hole or recess 14 in the soleholder member 3.

If the soleholder member is so designed that the radius of curvature of its retaining rib coincides with the axis of the pivotal movement of the skiing boot, an additional centering spring 7 as shown in FIG. 2 will be provided for urging the soleholder member to its normal position.

The soleholder member consists suitably of a material having a low coefficient of friction, e.g., a suitable plastics material. Alternatively, these surfaces of the soleholder member which contact the pivoted member may be coated with friction-reducing material.

In a toe iron according to the invention, the soleholder member follows the movement of the forward end of the boot within the damping zone so that there is no relative movement between the soleholder member and the skiing boot. In various known toe irons, such relative movement involves a high friction, which prevents an exact return movement after the action of forces which have not resulted in a release.

Iclaim: I

I. A toe iron for safety ski bindings mounted on a ski to be movable toward the tip of the ski, said toe iron engaging the forward end portion of a skiing boot from above and comprising a base, a pivoting member mounted to said base and movable in a substantially horizontal arcuate path, said pivoting member comprising a horizontally concave track in the form of an are or a circle provided in the rearward portion of said member, the radius of said track being not larger than the radius for the pivoted movement of the forward end of the skiing boot, said radius being measured from the heel support of the skiing boot, a soleholder member movably mounted in said track of said pivot member and means to limit the movement of said soleholdermember, said means comprising at least one stop, and centering means to urge said pivoting member to its normal position.

2. A toe iron according to claim 4, wherein the soleholder member is held in its normal position by at least one of said centering means.

3. A toe iron according to claim 2, wherein said centering means is a spring element. 

1. A toe iron for safety ski bindings mounted on a ski to be movable toward the tip of the ski, said toe iron engaging the forward end portion of a skiing boot from above and comprising a base, a pivoting member mounted to said base and movable in a substantially horizontal arcuate path, said pivoting member comprising a horizontally concave track in the form of an arc or a circle provided in the rearward portion of said member, the radius of said track being not larger than the radius for the pivoted movement of the forward end of the skiing boot, said radius being measured from the heel support of the skiing boot, a soleholder member movably mounted in said track of said pivot member and means to limit the movement of said soleholder member, said means comprising at least one stop, and centering means to urge said pivoting member to its normal position.
 2. A toe iron according to claim 4, wherein the soleholder member is held in its normal position by at least one of said centering means.
 3. A toe iron according to claim 2, wherein said centering means is a spring element. 